• Title, Summary, Keyword: chemical recycling

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Recycling of Polyurethane Scraps (폴리우레탄 스크랩의 재활용)

  • Kim, Han-Na;Lee, Dai-Soo
    • Elastomers and Composites
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    • v.47 no.2
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    • pp.104-110
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    • 2012
  • Depending on the states of polyurethane scraps generated in the production sites of polyurethane or recycling center of polyurethane scraps, appropriate recycling technologies can be employed for the recycling of resources. In this study, recycling technologies for the polyurethane scraps were classified into physical recycling, chemical recycling, and energy recycling and reports in the literatures were discussed.

Pilot Study on the Manufacture of Kraft Paper from OCC

  • Cho, Byoung-Uk;Ryu, Jeong-Yong;Song, Bong-Keun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.40 no.5
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    • pp.27-35
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    • 2008
  • In order to determine the most appropriate recycling line to treat old corrugated container (OCC) to substitute unbleached kraft pulp (UKP) for the manufacture of kraft paper, three recycling lines were evaluated in pilot scale tests. The recycling line consisting of kneading, flotation, washing, dispersion and screening steps was able to produce pulp with acceptable appearance. Kneading was shown to be more efficient treatment to reduce specks than dispersion. In addition, 0.2 mm slot screen was very effective to remove specks. Severe damages on fiber morphology such as shortening of fiber and formation of fines were not observed during mechanical treatments such as kneading and dispersion. Most of strength properties of the kraft paper produced with the recycled pulp were found to be slightly increased after treated in the recycling lines.

Status and Strategy on Recycling of Domestic Used Chemical Catalysts (국내 사용 후 화학촉매제품의 재자원화 현황 및 향후 방향)

  • Kim, Young-Chun;Kang, Hong-Yoon
    • Resources Recycling
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    • v.26 no.3
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    • pp.3-16
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    • 2017
  • Chemical catalyst products are applied to various fields such as petrochemical process, air pollution prevention facility and automobile exhaust gas purifier. The domestic and overseas chemical catalyst market is increasing every year, and the amount of waste catalyst generated thereby is also increasing. Most of the used chemical catalyst products, such as desulfurized waste catalysts and automobile waste catalysts containing valuable metals are important recyclable resources from a substitute resource point of view. The recycling processes for recovering valuable metals have been commercialized through some urban mining companies, and SCR denitration catalysts have been recycled through some remanufacturing companies. In this paper, the amount of domestic production and recycling of major catalyst products have thus been investigated and analyzed so as to be used as basic data for establishing industrial support policy for recycling of used chemical catalyst products. Also tasks for promoting the recycling of used chemical catalyst products are suggested.

Feedstock Recycling Technology from Polyester Wastes (폴리에스터 폐자원의 화학 원료화 기술)

  • Jo, Sanghwan;Kim, Gunhyung;Cho, Minjeong;Han, Myungwan;Kang, Kyungsuk
    • Korean Chemical Engineering Research
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    • v.52 no.1
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    • pp.17-25
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    • 2014
  • Wide spread application and non-biodegradability of the poly(ethylene terephthalate) generate a huge amount of waste and disposal, posing serious environmental problems. Disposal of the PET wastes also can be thought as an economic loss of valuable chemical resources. We present various ways of feedstock recycling of PET waste to deal with environmental and economic problems. Feedstock recycling is one of promising technologies. It is based on the concept of depolymerizing the condensation polymer such as PET through solvolytic chain cleavage into low molecular products which can be purified and reused as raw materials for the production of high quality chemical products.

Trend for Waste Plastic Recycling Technology by Patent Analysis (특허분석(特許分析)에 의한 폐플라스틱 재활용(再活用) 기술(技術) 동향(動向))

  • Kim, Tae-Hyun;Rhee, Kang-In;Kim, Yu-Ri
    • Resources Recycling
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    • v.19 no.2
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    • pp.63-72
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    • 2010
  • The patents were searched to investigate the trend of recycling technologies about plastic waste. Database was collected from WIPS site and the range of the search was limited to patents opened in U.S.A (US), European Union (EU), Japan (JP) and Korea (KR) to september 2009. In this paper, 4,795 patents were selected by investigation abstracts and the trend of the recycling technologies relating to waste plastic were investigated through the analyzing by the years, countries, companies. The patents were occupied 65% by Japan and the most of the patents were about chemical recycling. In the case of Korea, material recycling was major in the patents of waste plastic recycling.

Chemical Recycling Technology from Polyester Wastes (폴리에스터 폐자원의 화학적 재활용기술)

  • Han, Myung-Wan;Kang, Kyung-Suk;Song, Jae-Kyung
    • Elastomers and Composites
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    • v.47 no.2
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    • pp.96-103
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    • 2012
  • This paper reviews recent technologies for recycling poly (ethylene terephthalate) wastes. Wide application and non-biodegradability of the PET creates huge amounts of waste and disposal, leading to an environmental problem and economic loss. Chemical recycling can be a promising technology to deal with these problems by converting the waste into useful feedstock material for polyester production. Chemical recycling of polyethylene terephthalate are processes where the PET polymer chain is destructed by the impact of glycol (MEG) causing glycolysis, methanol causing methanolysis or water causing hydrolysis. After intensive purification polyester oligomers or the monomers MEG, dimethyl telephthalate (DMT) or purified terephthalic acid (PTA) are received which are re-used to produce polyester products.

Depolymerization of Waste Polyurethane from Automotive Seats (자동차 시트용 폐폴리우레탄의 해중합)

  • Min, Sung-Jin;Kong, Seung-Dae;Yoon, Cheol-Hun;Kang, An-Soo;Eom, Jae-Yeol;Shin, Pan-Woo;Lee, Seok-Woo
    • Journal of the Korean Applied Science and Technology
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    • v.18 no.2
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    • pp.103-110
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    • 2001
  • Resource recovery and recycling of materials and products, including polyurethanes is viewed as a necessity in today's society. Most urethane polymers are made from a polyol and a diisocyanate. these and be chemicals such as water, diamines or diols that react with isocyanate groups and add to the polymer backbone. The problems of recycling polyurethane wastes has major technological, economic and ecological significance because polyurethane itself is relatively expensive and its disposal whether by burning is also costly. In general, the recycling methods for polyurethane could be classified as mechanical, chemical and feedstock. In the chemical recycling method, there are hydrolysis, glycolysis, pyrolysis and aminolysis. This study, the work was carried out glycolysis using sonication ant catalyzed reaction. Different kinds of recycled polyols were produced by current method(glycolysis), catalyzed reaction and sonication as decomposers and the chemical properties were analyzed. The reaction results in the formation of polyester urethane diols, the OH value which is determined by the quantity of diol used for the glycolysis conditions. The glycolysis rates by sonication for the various glycols, increased as fallows: PPG